This invention relates generally to projectiles, and more particularly, to composite projectiles and ammunition incorporating composite projectiles.
Conventional small arms ammunition comprises a cartridge having a casing loaded with a propellant powder and a projectile (e.g., a bullet). An impact-sensitive primer ignites the propellant when struck by a gun's firing pin. Projectiles for such ammunition are most typically made from lead or lead alloys. This material has a high density providing good velocity retention, range, muzzle energy, and target penetration, while being soft enough not to engage the rifling in a barrel without damaging the barrel.
Unfortunately, lead is a source of both indoor and outdoor pollution, and is also rising in cost. Attempts have been made in the prior art to replace lead in projectiles. However, these materials have either been expensive (e.g., tungsten) or have significant performance limitations in terms of structural integrity and target penetration (e.g., polymers). Furthermore, even when projectiles are made from lead, their expansion characteristics (and related temporary and permanent wounding effects) are limited when incorporated into pistol ammunition, because of the relatively low muzzle energy levels that can be safely generated in a pistol. This limits the so-called “stopping power” of conventional pistol ammunition.
Other attempts have been made to replace lead in projectiles, as evidenced, for example, by U.S. Pat. No. 5,237,930; U.S. Pat. No. 5,399,187; U.S. Pat. No. 5,616,642; U.S. Pat. No. 5,786,416; U.S. Pat. No. 6,048,379; U.S. Pat. No. 6,630,231; U.S. Pat. No. 6,823,798; and U.S. Pat. No. 8,689,696.
With regard to composite projectiles that have been made in accordance with one or more embodiments disclosed in U.S. Pat. No. 8,689,696—and ammunition incorporating such composite projectiles, it is believed that such projectiles may tumble when fired from a pistol or rifle. While not necessarily disadvantageous at short distances typically encountered in self-defense shootings, tumbling can be disadvantageous when shooting at medium and long range distances, as tumbling is believed to result in a loss of shooting accuracy and precision. Conventionally, spinning of a projectile about the longitudinal axis of a barrel of a pistol or rifle resulting from the rifling of a barrel is believed to keep the projectile from tumbling. The composite projectiles that have been made in accordance with one or more embodiments disclosed in U.S. Pat. No. 8,689,696 are believed to be of insufficient diameter and/or insufficient in some other characteristic (e.g., too ‘soft’) for adequately engaging rifling of a barrel so as to impart rotation to the projectile as it advances through the barrel.
In view of the foregoing, it is believed that a need exists for a way of providing spinning to composite projectiles that are made in accordance with one or more embodiments disclosed in U.S. Pat. No. 8,689,696. One or more aspects and features of the present invention are believed to address such perceived need.